Cable restraint

ABSTRACT

A device for receiving a cable therethrough and permitting substantially free movement of the cable in a first direction but resisting cable movement in an opposite direction until the forces exerted thereon exceed a predetermined minimum and thereafter permitting free cable movement in said opposite direction.

United States Patent 1 91 Fuller I [11] 3,729fi68 1451 Apr. 24 1973CABLE ,RESTRAINT [75 Inventor: Harry V. Fuller, Newport News, Va.

[73] Assignee: The United States of America as represented by theAdministrator of the National Aeronautics and Space Administration [22]1 Filed: Dec. 17, 1970 [21] Appl. No.: 99,201

52 U.S.Cl .188/65.l,24/l34 R, 182/5,

, v I 254/156 1 51 Int. CL... ..B65h 59/16 [58 FieldofSearch..l88/65.1,67, 65.5;

254/156; 24/134 R, 134 E, 134 EA, 134 N, 254; 74/531; 182/5, 7

[ 56] References Cited UNITED STATES PATENTS Ball .24/l 34 R 1,033,31 l7/1912 GillOOn et a] ..254/l56 1,226,221 5/1917 Keator ..24/l34 R1,482,268 1/1924 SchOpper 188/65. 1 2,867,875 1/1959 Davison ..24/134 RX Primary Examiner-George E. A. l-lalvosa Att0rney-Wallace J. Nelson,Howard J. Osborn and John R. Manning [57] ABSTRACT A device forreceiving a cable therethrough and permitting substantially freemovement of the cable in a first direction but resisting cable movementin an opposite direction until the forces exerted thereon exceed apredetermined minimum and thereafter permitting free cable movement insaid opposite direction.

4 Claims, 5 Drawing Figures Pat ented April 24, 1973 FIG. 1

A r TORNE vs Patented April 24, 19.73 3,729,068

2 Sheets-Sheet 2 I N VENTOR. HARRY v. FULLER ATT'ORNE Ys CABLE RESTRAINTThis invention relates to a cable guide and restraint device and relatesin particular to a reefing system for a pliable tube employing aplurality of these devices that permit the tube to be freely expandedand assist in reefing the tube in a uniform manner.

In various operations on interplanetary vehicles planned it iscontemplated that certain operationsperformed thereon be conducted incompletely sterile conditions. These operations must be performed in asterile room and care must be taken to see that the isolatedsterile roomis not contaminated by earth organisms that may be carried by theworkers in the room. One system proposed for use under these conditionsis the bio-isolator suit system (BISS) in which a sterile room workerenters a folded tube attached to the wall of the room and dons asterilized suit sealed on the end thereof. Once in the sterile suit theoccupant may move about the sterile room by exerting force on the foldedtube and perform the necessary functions in the area without danger ofcontaminating the sterile room. A system of this type is furtherdescribed in an application filed Oct. 27, 1970, Ser. No. 84,290. Oneproblem that has somewhat hampered the development of a system of thistype has been the reefing of the expanded tube or tunnel in such manneras to prevent tangling thereof. The present invention appears to solvethis and other problems in this area.

It is therefore an object of the present invention to provide a new andnovel system for reefing a pliable tube.

Another object of the present invention is a new and novel cablerestraint.

A further object of the present invention is a cable restraint thatpermits free movement of the cable in a first direction but resistsmovement in an opposite direction until the force exerted thereonexceeds a predetermined minimum.

An additional object of the present invention is a system for gatheringa pliable tube one fold at a time until all the material in the tube hasbeen folded and thereafter permitting the extension of the tube with aminimum of resistance.

These and other objects of the present invention are attained by the useof a plurality of unique cable restraints. Each of these cablerestraints are constructed to permit the passage therethrough of a cableand to permit substantially unimpeded sliding movement of the cable in afirst direction but to restrain a cable from movement in a seconddirection until the forces exerted thereon exceed a predeterminedamount. The cable restraints are disposed as diametrically opposed pairsspaced along the length of two cables extending the length of thepliable tube. One end of each cable is connected to a winch adjacent thebulkhead on which the pliable tube is mounted and the other end of eachcable is attached to a terminal block at the end of the pliable tubeconnected with the sterile suit. When an occupant dons the sterile suitthrough the folded pliable tube he may walk and expand the pliable tubewith little or no resistance from the cable restraints. When it isdesired to return the pliable tube to its stowabie condition the pair ofwinches are actuated to exert a constant force on the pair of cables andall the restraints, and the attached tubing material are drawn towardthe entrance bulkhead. As the first pair of cable restraints are drawnagainst a stop adjacent the winches, the tube material is drawnthereagainst by the connection between the tube material and this pairof restraints. The force exerted by the winches is sufficient toovercome the springs within the cable restraints and the restraintsbearing against the stop permit the cables to slip therethrough. Theremaining restraints, the suit and tubing continues to move with thecables. Thus, the tube material which is between the first pair ofrestraints which have been stopped, and the second pair which are stillmoving will begin to fold and continue folding until the second pair ofrestraints are stopped by the first stopped pair. Each succeeding pairof restraints will stop, in turn, and the material between it and thesucceeding restraint pair will fold until the last pair and the terminalblocks are brought up to a positive stop against all the previous pairs.The tubular tunnel will then have been fully folded for stowage. Whenthe suited operator walks away from the entrance wall the winch drumshave been released from the gear resistance and since the cablerestraints are designed to permit free sliding movement of the cable inone direction, the operator can walk away with only the tunnel dragoffering resistance to his move ment.

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily appreciated as the same becomesbetter understood by reference to the following detailed descriptionwhen considered in connection with the accompanying drawings wherein:

FIG. 1 is a top plan view of a bio-isolator suit system in 'the foldedor stowed condition and employing the reefing system of the presentinvention;

FIG. 2 is a view of the system shown in FIG. 1 in the open or extendedposition;

FIG. 3 is a section of one cable restraint according to the presentinvention;

FIG. 4 is a section of the cable restraint shown in FIG. 3 and takenalong line 44 of FIG. 3; and

FIG. 5 is a section of the cable restraint shown in FIG. 3 and takenalong line 55 of FIG. 3.

Referring now to the drawings and more particularly to FIGS. 1 and 2,there is shown a tube reefing system according to the present inventionand generally designated by reference numeral 10. The pliable tube 1 1with the attached sterile suit 12 is shown in the compact or reefedcondition in FIG. 1 as it would appear in a sterile compartment havingan inner wall 13 with an opening 14 therein for sealed attachment of thetunnel or tube 11. The material making up tube 11 can be anyconventional pliable cloth, plastics or the like that is not permeableto air, water, or microorganisms and that will withstand thesterilization procedures employed for the sterile chamber.

A pair of winches 20 and 21 are disposed on diametric opposite sides oftube 11 adjacent wall 13. A pair of reefing cables 23 and 24 areconnected to the respective winches 20 and 21 and extend slidablythrough respective stop members 26 and 27 and around respective pulleys30 and 31. A plurality of cable restraints, two of which are designatedby reference numerals 33 and 34, are disposed along the length of cables23 and 24. The ends of cables 23 and 24 opposite to that connected towinches 20 and 21 are attached to respective terminal blocks 36 and 37disposed adjacent suit 12 on diametrically opposed sides of tube 11.Terminal blocks 36 and 37, cable restraints 33 and 34 and the remainingcable restraints, not designated, are maintained in pairs diametricallyopposed to each other and spaced from tube 11 by a plurality of rigidconnectors 39, 40 and others not designated. These connectors may beformed of rigid plastics, lightweight metal or the like and are fastenedto the material making up tube 11 to prevent relative movement therewithas will be further explained hereinafter. The tube 11 is shown herein ashaving only three pairs of cable restraints for purposes of illustrationand simplicity only, it being understood that in practice any number ofcable restraints may be employed for reefing of the tube material.

Referring now more particularly to FIGS. 3, 4 and the details of onecable restraint, generally designated by reference numeral 34, will nowbe described, it being understood that each of the cable restraintsemployed are of identical construction and operation. Restraint 34includes a rectangular housing 41 closed at the ends by a top closure 42and a bottom closure 43. An opening 45 extends through housing 41 topermit the passage therethrough of cable 24. A resisting anvil 46 ispositioned within housing 41 and serves as a smooth surface for cable 24to slide thereon. Anvil 46 is slidably received in housing 41 and isprovided with an adjusting screw 47 rotatably received at the basethereon. Adjusting screw 47 is threadingly received by bottom closure 43and serves to adjust the position of anvil 46 within housing 41. A locknut 48 is positioned about adjusting screw 47 to lock the screw in thedesired position in a conventional manner. A bracket 51 is integrallyattached to top closure 42 with an elongated cam holder 52 pivotallyconnected thereto by way of pivot pin 53. The other end of cam holder 52is bifurcated to receive friction cam 55 which is pivotally connectedthereto by way of pivot pin 56. One end of friction cam 55 is serratedas shown in FIG. 3 and is adapted to engage cable 24 and exert a forceon the cable portion resting on resisting anvil 46. Friction cam 55 isnormally maintained against structure formed by the bifurcated end ofcam holder 52 by a weak leaf spring 58. Thus, one side of thebifurcation is substantially closed (the left side as shown in FIG. 3)while the other side of the bifurcation is open to permit friction cam55 to freely pivot therein as will be more fully described hereinafter.Leaf spring 58 is fixedly attached at one end to a spring holder 59integral with cam holder 52. The other end of spring 58 is secured topin 61 integrally attached to friction cam 55.

Cam holder 52 is normally maintained in the vertical position shown inFIG. 3 under the influence of spring 63 attached thereto at one end withthe other end being attached to housing 41. Spring 63 is normally undertension to maintain cam holder 52 against a stop 64 integrally extendingfrom a sidewall of housing 41.

OPERATION The operation of the invention is now believed apparent. Whenutilizing the cable restraints 33, 34 and others, not designated, in atube reefing system 10, ca-

bles 23 and 24 are connected as shown in FIGS. 1 and 2 with the cablespassing through each restraint as shown in FIG. 3 for cable 24 andrestraint 34. When the operator enters folded tube 11 (FIG. 1) and donssuit 12 he may walk away from wall 13 of the sterile chamber withsubstantially the only resistance being offered by the weight of thematerial making up tube 11. Thus, cables 23 and 24 would move in thedirection of the arrow 67 to cause friction cam 55 to pivot to the leftas shown in this figure resisted only by the weak spring 63 to releasecable 24 from frictional tension. The drums of winches 20 and 21 aredisengaged from the gearing therein during this operation to permit freerotation thereof. After completion of the tasks performed by theoperator of suit 12, tube 11 may be reefed by actuating winches 20 and21 to exert a force on cables 23 and 24. This force is exerted in thedirection of the arrow 66 (FIG. 3) on each of the cables. When thesynchronized winches are started all the restraints, both cables, andthe attached tubing and suit are drawn toward wall 13. When the firstpair of restraints near wall 13 reach stop members 26 and 27 they arestopped thereby and no cable movement can occur until the predeterminedset force resistance on the cables is exceeded. This set resistance iscontrolled by the position of the anvil 46, (FIG. 3). Thus, cam holder52 maintains friction cam 55 in positive engagement with cable 24 when aforce is exerted thereon in the direction of arrow 66. When this forceovercomes the cable 24 resistance to compression, cam 55 will pivotabout pivot pin 56 (to the right as shown in FIG. 3) and permit cable 24to move with no additional resistance. The remaining restraints, suit 12and tube 11 will continue to move along with the cables. Consequently,the tube material which is between the first pair of restraints whichhave been stopped, and the second pair of restraints which are stillmoving will begin to fold and will continue to fold until the secondpair of restraints bear against the first pair and are stopped thereby.Each pair of restraints will stop, in turn, and the material between itand the succeeding device will fold until the terminal blocks 36 and 37are brought to a positive stop against all the previous pairs ofrestraints as shown in FIG. 1. The tube will then be fully folded andstored.

There are many modifications and variations of the invention that willbe readily apparent to those skilled in the art in the light of theabove teachings. For example, leaf spring 58 may be replaced by a coilspring received about pivot pin 56 and attached to cam holder 52 andfriction cam 55. Also, a constant force spring could be positionedbetween adjusting screw 47 and resisting anvil 46 if so desired.Although the cable restraints have been described relative to a tunnelreefing system the invention is not so limited and any use thereof whereit is desired that a structure resists a force of a predetermined amountand thereafter release structure for movement in response to the forceis considered within the teachings of this invention. For example, thecable restraints described herein could be employed as a governor on ahopper or the like, where a fixed weight would be attached to one end ofthe cable with the cam holder 52 and cam 55 being designed to release atrap door when the load exerted thereon exceeded the fixed weight. Theseand other modifications and variations are considered possible in thelight of the above teachings.

It is therefore to be understood that the invention may be practicedotherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. A cable restraint comprising;

a housing having a passageway therein for receiving a cablethe'rethrough,

first and second end closures for said housing,

means attached internally within said housing for permitting said cableto be substantially freely movable relative to said housing in a firstdirection in response to a force exerted thereon and serving to restrainsaid cable from relative movement in an opposite direction to said firstdirection until a predetermined force is exerted on said cable in saidopposite direction and thereafter permitting on said cable by saidfriction cam and said anvil,

d. said friction cam being pivotally connected to acam holder and saidcam holder being pivotally connected to a bracket integrally connectedto the other of said end closures,

e. spring means normally biasing said cam holder toward a perpendicularrelationship with said passageway in said housing, and,

f. stop means connected to said housing serving to engage said camholder and limit movement thereof in one direction, said cam holderbeing substantially freely pivotally movable in an opposite directionwhen forces are exerted thereon by said cable in said oppositedirection.

2. A cable restraint as in claim 1 and further including:

limit means on said cam holder for limiting pivotal movement of saidfriction cam in a first direction, weak spring means carried by said camholder normally biasing said friction cam against said limit means.

3. A cable restraint as in claim 2 wherein said friction cam includes aserrated surface for contacting said cable.

4. A cable restraint as in claim 3 wherein said cam holder is providedwith a bifurcated end, said friction cam being pivotally connected tosaid cam vholder within said bifurcated end, and portions of said camholder serving as said limit means.

1. A cable restraint comprising: a housing having a passageway thereinfor receiving a cable therethrough, first and second end closures forsaid housing, means attached internally within said housing forpermitting said cable to be substantially freely movable relative tosaid housing in a first direction in response to a force exerted thereonand serving to restrain said cable from relative movement in an oppositedirection to said first direction until a predetermined force is exertedon said cable in said opposite direction and thereafter permitting cablemovement relative to said housing in said opposite direction, said meansattached internally within said housing including, a. a resisting anvilhaving a smooth surface extending the width of said housing andpermitting said cable to freely slide thereon, b. a friction cam forengaging and compressing said cable against said resisting anvil, c.adjustment structure including an adjusting screw and lock washerextending through one of said end closures to adjust the frictionexerted on said cable by said friction cam and said anvil, d. saidfriction cam being pivotally connected to a cam holder and said camhoLder being pivotally connected to a bracket integrally connected tothe other of said end closures, e. spring means normally biasing saidcam holder toward a perpendicular relationship with said passageway insaid housing, and, f. stop means connected to said housing serving toengage said cam holder and limit movement thereof in one direction, saidcam holder being substantially freely pivotally movable in an oppositedirection when forces are exerted thereon by said cable in said oppositedirection.
 2. A cable restraint as in claim 1 and further including:limit means on said cam holder for limiting pivotal movement of saidfriction cam in a first direction, weak spring means carried by said camholder normally biasing said friction cam against said limit means.
 3. Acable restraint as in claim 2 wherein said friction cam includes aserrated surface for contacting said cable.
 4. A cable restraint as inclaim 3 wherein said cam holder is provided with a bifurcated end, saidfriction cam being pivotally connected to said cam holder within saidbifurcated end, and portions of said cam holder serving as said limitmeans.